Steel Turns Real in Animal Artwork

Raster-to-vector conversion software is key in Paley Studios' quest to create the world's largest public zoo sculpture

The size of the Animals Always sculpture, which lies at the entrance of the St. Louis Zoo, is impressive in itself. Measuring 130' long, 36' high and 8' deep -- reportedly the world's largest public zoo sculpture -- it features more than 60 recognizable animals, including elephants, penguins, giraffes and a giant salamander.

Also impressive is the technology that proved to be key in transforming an artistic concept into a gigantic steel artwork.

The idea for the sculpture, designed by Albert Paley of Paley Studios, originated nearly 20 years ago. The current design incorporates Paley's inspiration developed from more than three years of collaborating with the St. Louis Zoo and local authorities as well as from taking an architectural tour of the St. Louis, Missouri, area.

Paley stands before his Animal Always sculpture. (Photo courtesy of the St. Louis Zoo)

"It's about how we relate to a threatened environment," Paley says of the thinking behind the scuplture. "I'm glad to be associated with the zoo, which is involved with many international programs to save endangered species. I went to zoos -- including the Seneca Park Zoo [Rochester, New York] -- and drew a lot of animals. The challenge was personalizing these animal designs. I love challenges, but this has been a huge undertaking."

Paley began by transforming his sketches into a 3D cardboard model, a process that took nearly six months. The challenge for the Paley Studios team was taking that cardboard model and Paley's 2D drawings and creating computer images for cutting the steel for the actual sculpture.

Capturing the Design
Robert Chan, Paley Studios project manager, needed an efficient way to transfer the extensive sculpture details to AutoCAD. After evaluating various products, the studio chose Scan2CAD from Softcover. "It seemed to do the best job of converting our scanned images saved as TIF files into DXF," Chan said.

Scan2CAD is a raster-to-vector converter that turns scanned raster images into DXF files suitable for editing in a PC CAD program. Chan had two requirements for Scan2CAD. The first was that its DXF files had to closely match to Paley's 2D drawings. The second was that the converted files would require minimal clean-up in AutoCAD.

By first creating good-quality scans of the drawings, Paley Studios followed a set raster-to-vector conversion procedure in Scan2CAD. Scan2CAD converted the 2D drawings into a tight-fitting DXF file made up from lines, polylines or Bezier curves (which can be exported to AutoCAD as splines, polylines or arcs).

Unintended Advantage
Paley Studios discovered an unanticipated benefit in its use of CAD technology. Not only could the studio equip its steel supplier with patterns in a CAD file, but any pattern could be easily resized to produce a scale model of the design in COR-TEN, the steel material that has a rusty appearance and is popular for use in outdoor sculptures.

Fabricating the sculpture. (Photo courtesy of Bruce Miller)

"Scan2CAD has greatly increased our flexibility to control our patterns," Chan says. "Now, each piece can be burned to our specifications or modified without having to recreate the paper pattern and pay for extra time on the burn table. Our integration of Scan2CAD raster-to-vector conversion technology with AutoCAD has developed time- and cost-saving factors which Paley Studios will use well into the future."

Animals Always traveled more than 800 miles on a cross-country caravan from New York to St. Louis. Fourteen flatbed trucks carried more than 1,300 parts that make up the completed sculpture, which now sits at the intersection of Hampton Avenue and Wells Drive at the zoo. The opening ceremony for the sculpture was held in May 2006.

The sculpture was funded by two gifts from Thelma Zalk and the Steven F. Schankman family. Zalk donated $1 million for the fabrication of the sculpture, and the Schankman family donated $1 million to build the plaza to house it.

A close-up of part of the Animal Always sculpture at its new home in St. Louis. (Photo courtesy of Lou Bopp)

"I am so pleased that Animals Always has found a home in St. Louis," says Paley. "Never have I received such a warm welcome in such a wonderful community. Animals Always is my most complex work to date, and that coupled with the fact that it is my first representational work makes it very special to me. I'm proud to say that it is now a symbol of preservation and welcome at this world-class park, zoo and city."

About the Author: Michelle Nicolson

Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!Follow Lynn on Twitter